Israeli ID Validator (Javascript)

IsraeliID.Validator.js

function isValidIsraeliID(id) {
	var id = String(id).trim();
	if (id.length > 9 || id.length < 5 || isNaN(id)) return false;

	// Pad string with zeros up to 9 digits
  	id = id.length < 9 ? ("00000000" + id).slice(-9) : id;

  	return Array
            .from(id, Number)
  		    .reduce((counter, digit, i) => {
		        const step = digit * ((i % 2) + 1);
                        return counter + (step > 9 ? step - 9 : step);
    	            }) % 10 === 0;
}

// Usage
["1234567890","001200343", "231740705", "339677395"].map(function(e) {
	console.log(e + " is " + (isValidIsraeliID(e) ? "a valid" : "an invalid") + " Israeli ID");
});

// Outputs: 
// 1234567890 is an invalid Israeli ID
// 001200343 is an invalid Israeli ID
// 231740705 is a valid Israeli ID
// 339677395 is a valid Israeli ID

String+IsraeliID.swift

extension String {
    func isValidIsraeliID() -> Bool {
        let trimmed = trimmingCharacters(in: .whitespacesAndNewlines)
        let isNumeric = rangeOfCharacter(from: CharacterSet.decimalDigits.inverted) == nil
        
        guard 1...9 ~= trimmed.count,
              isNumeric else { return false }
        
        let neededZeros = 9 - trimmed.count
        let tested = String(repeating: "0", count: neededZeros) + trimmed
        
        return tested.enumerated()
            .reduce(into: 0) { counter, args in
                let (idx, char) = args
                guard let digit = char.wholeNumberValue else { return }
                let step = digit * ((idx % 2) + 1)
                
                counter += step > 9 ? step - 9 : step
            } % 10 == 0
    }
}

Hey, do you have code for company id numbers as well?
Or maybe just know what the basic rules are for those?

Thanks.

This is an ancient algo that's present many years: https://gist.github.com/adi518/84214b150357291e7523179c331f3bc1

I slightly updated it, but it misses padding. My point though, does it differ logic-wise? If not, I guess you should put yours on npm. There's one entry on npm atm, but it lacks padding and source is not as good. :)

Don't need var here: var id = String(id).trim();.

hello, is there anyway to turn this into a regexp ?
thanks

@landesm Don't see how. Regex is for matching, not complex computation.

@freak4pc
Thank you for the swift version!